Imidazoquinoline derivatives

ABSTRACT

The present invention relates to adenosine A 3  receptor ligands of the general formula (I), within those preferably antagonists, as well as their salts, solvates and isomers, and the pharmaceutical compositions containings them, to the use of the compounds of the general formula (I), as well as their salts, solvates and isomers, to the preparation of the compounds of the general formula (I) and (heir salts, solvates and isomers, furthermore to the new intermediates of the general formulae (II) and (III) and to the preparation thereof.

The present invention relates to adenosine A₃ receptor ligands of the general formula (I), within those preferably antagonists, as well as their salts, solvates and isomers, and the pharmaceutical compositions containing them, to the use of the compounds of the general formula (I), as well as their salts, solvates and isomers, to the preparation of the compounds of the general formula (I) and their salts, solvates and isomers, furthermore to the new intermediates of the general formulae (II) and (III) and to the preparation thereof.

Adenosine is a well-known component of several endogenous molecules (ATP, NAD⁺, nucleic acids). Besides, it plays an important regulatory role in many physiological processes. The effect of adenosine on heart function was discovered already in 1929. (Drury and Szentgyörgyi, J Physiol 68:213, 1929). The identification of an increasing number of physiological functions mediated by adenosine and the discovery of new adenosine receptor subtypes give possibilities for therapeutic application of specific ligands (Poulse, S. A. and Quinn, R. J. Bioorganic and Medicinal Chemistry 6:619, 1998).

To date, the receptors for adenosine have been classified into three main classes: A₁, A₂ and A₃. The A₁ subtype is partly responsible for inhibiting the adenylate cyclase by coupling to G_(i) membrane protein, partly influences other second messenger systems. The A₂ receptor subtype can be subdivided into two further subtypes—A_(2a) and A_(2b)—, which receptors stimulate the adenylate cyclase activity. The sequence of adenosine A₃ receptors has been recently identified from rat testis cDNA library. Later it was proved that it corresponds to a novel, functional adenosine receptor. The activation of the A₃ receptors is connected also with several second-messenger systems: e.g. inhibiting of adenylate cyclase, and stimulating of phospholipase C and D.

The adenosine receptors are found in several organs and regulate their functions. Both A₁ and A₂, receptors play important roles in the central nervous system and cardiovascular system. In the CNS, the adenosine inhibits the release of synaptic transmitters which effect is mediated by A₁ receptors. In the heart, also the A₁ receptors mediate the negative inotropic, chronotropic and dromotropic effects of adenosine. The adenosine A_(2a) receptors located relatively in a higher amount in the striatum, display a functional interaction with dopamine receptors in regulating the synaptic transmission. The A_(2a) adenosine receptors on endothelial and smooth muscle cells are responsible for adenosine-induced vasodilation.

On the basis of mRNA identification, the A_(2b) adenosine receptors are widely distributed in different tissues. They have been identified almost in every cell type but its expression is the highest in the intestine and the bladder. This subtype probably also has important regulatory function in the regulation of the vascular tone and plays a role in the function of mast cells.

Contrary to A₁ and A_(2a) receptors, where the tissue distribution was detected on the protein level, the presence of A_(2b) and A₃ receptors was detected on the basis of their mRNA level. Expression levels for A₃ adenosine receptors are rather low comparing to other subtypes and highly species dependent. A₃ adenosine receptors are expressed primarily in the central nervous system, testis, immune system and appear to be involved in the modulation of mediator release from mast cells in immediate hypersensitivity reaction.

The A₃ antagonists published so far in the literature belong to the groups of flavonoides, 1,4-dihydropyridine derivatives, triazoloquinazolines, thiazolonaphthyridines and thiazolopyrimidines. The present invention relates to a novel type of effective A₃ antagonists, which have the imidazoquinlolin structure.

For therapeutic use it is essential to ensure that the molecule does not bind, or bind only in the case of very high concentration to the A₁, A_(2a) and A_(2b) sub-types of the adenosine receptor. Our present invention relates to the compounds of the general formula (I) as well as their salts, solvates and isomers which have great selectivity for the A₃ sub-type of the adenosine receptor.

Our aim was to prepare A₃ ligands first of all with imidazoquinolin structure, and within those preferably antagonists, which have strong antagonistic effect and show high selectivity for the A₃ receptor, ie. they inhibit the A₃ receptor in much lower concentration than they inhibit the A₁, A_(2a) and A_(2b) receptors. Further aims were to have stability, bioavailability, therapeutic index and toxicity data which make possible to develope the new compounds into drug substances and that due to their favourable enteral absorbtion the compounds can be applied orally.

We have found that the compounds of the general formula (I)—wherein

-   -   R¹ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl         group;     -   R² stands for hydrogen atom or a straight or branched C₁₋₄ alkyl         group;     -   R³ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl         group, or C₃₋₆ cycloalkyl group, or a phenyl group, thienyl         group, or furyl group, optionally substituted by one or more         straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄         alkoxy group, or halogen atom, or for a 5- or 6 membered         heteroaromatic ring-containing one, two or three nitrogen atoms         or a 5 membered heteroaromatic ring containing one nitrogen atom         and one oxygen atom or one nitrogen atom and one sulphur atom,         optionally substituted by one or more straight or branched C₁₋₄         alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen         atom;     -   R⁴, R⁵, R⁶ and R⁷ stand independently from each other for         hydrogen atom, a straight or branched C₁₋₄ alkyl group, straight         or branched C₁₋₄ alkoxy group, hydroxy group or halogen atom; or         R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a         methylenedioxy group     -   R⁸ stands for hydrogen atom or a cyano group, aminocarbonyl         group, C₁₋₄ alkoxycarbonyl group, or carboxy group;     -   R⁹ and R¹⁰ stand independently from each other for hydrogen atom         or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl         group, or a phenyl group, phenyl-(C₁₋₄)alkyl group,         thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally         substituted by a methylenedioxy group, or one or more straight         or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy         group, hydroxy group, trifluoromethyl group, cyano group or         halogen atom, or for a 5 or 6 membered heteroaromatic ring,         containing one, two or three nitrogen atoms, or a 5 membered         heteroaromatic ring, containing one nitrogen atom and one oxygen         atom or one nitrogen atom and one sulphur atom, optionally         substituted by one or more straight or branched C₁₋₄ alkyl         group, straight or branched C₁₋₄ alkoxy group, or halogen atom;         or for a —(CH₂)_(m)—OH or —CH₂)_(o)—NR¹²R¹³ group, or     -   R⁹ and R¹⁰ form together with the nitrogen atom a 3-7 membered         heterocyclic group, optionally substituted by a straight or         branched C₁₋₄ alkyl group;     -   R¹² and R¹³ stand independently from each other for hydrogen         atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆         cycloalkyl group, or a phenyl group, phenyl-(C₁₋₄)alkyl group,         thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄ )alkyl group,         optionally substituted by a methylenedioxy group, or one or more         straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄         alkoxy group, hydroxy group, trifluoromethyl group, cyano group         or halogen atom, or for a 5 or 6 membered heteroaromatic ring,         containing one, two or three nitrogen atoms, or a 5 membered         heteroaromatic ring, containing one nitrogen atom and one oxygen         atom or one nitrogen atom and one sulphur atom, optionally         substituted by one or more straight or branched C₁₋₄ alkyl         group, straight or branched C₁₋₄ alkoxy group, or halogen atom,         or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³ group, or     -   R¹² and R¹³ form together with the nitrogen atom a 3-7 membered         heterocyclic group, optionally substituted by a straight or         branched C₁₋₄ alkyl group     -   X stands for a —CH₂— group, —NH— group, —NR¹¹— group, or a         sulphur atom or an oxygen atom or a sulpho group or a sulphoxy         group—wherein R¹¹ stands for a straight or branched C₁₋₄ alkyl         group or C₃₋₆ cycloalkyl group;     -   n stands for zero, 1 or 2     -   m stands for 1, 2, 3 or 4, and     -   o stands for zero, 1, 2, 3 or 4 and their salts, solvates, and         their optically active isomers and the salts, solvates thereof     -   fulfil the above criteria.

Detailed meanings of the above listed substituents are as follows:

By a straight or branched C₁₋₄ alkyl group we mean methyl-, ethyl-, propyl-, isopropyl-, butyl-, isobutyl-, secondary-butyl-, terciary-butyl-, preferably ethyl- or methyl group.

By a straight or branched C₁₋₄ alkoxy group we mean methoxy-, ethoxy-, propoxy-, isopropoxy-, butoxy-, isobutoxy-, secondary-butoxy-, terciary-butoxy-, preferably ethoxy- or methoxy group.

By a C₃₋₆ cycloalkyl group we mean cyclopropyl-, cyclobutyl-, cyclopentyl- or cyclohexyl group.

By a 3-7 membered heterocyclic ring we mean dimethyleneimine (aziridine), trimethyleneimine, tetramethyleneimine (pyrrolidine), pentemethylenimine (pyperidine) or hexamethyleneimine group.

The heteroaromatic ring containing one or two or three nitrogen atoms means pyrrol, imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, pyridine, pyrimidine, pyridazine, pyrazine and 1,3,4-triazine ring. The ring is optionally substituted by a C₁₋₄ alkyl, or alkoxy group or by a halogen atom.

The heteroaromatic ring containing one nitrogen atom and one oxygen or sulphur atom means oxazole, isoxazole, thiazole, isothiazole ring. The ring is optionally substituted by a C₁₋₄ alkyl, or alkoxy group or by a halogen atom.

Salts of the compounds of the general formula (I) mean salts given with inorganic and organic acids and bases. Preferred salts are those given with pharmaceutically accepted acids as for instance hydrochloric acid, sulphuric acid, ethanesulphonic acid, tartaric acid, succinic acid, fumaric acid, malic acid, citric acid, and bases, as for instance sodium hydroxide, potassium hydroxide, ethanolamine.

Solvates mean solvates given with various solvents, as for instance with water or ethanol.

The compounds of the general formula (I) show geometric and optical isomerism, therefore the invention also relates to mixtures of the geometric isomers, to racemic or optically active geometric isomers, as well as to their salts and solvates.

A favourable group of the compounds of the general formula (I) is formed by the compounds of the general formula (IA), wherein

-   -   R¹ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl         group;     -   R² stands for hydrogen atom or a straight or branched C₁₋₄ alkyl         group;     -   R³ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl         group, or a C₃₋₆ cycloalkyl group or a phenyl group, thienyl         group, or furyl group, optionally substituted by one or more         straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄         alkoxy group, or halogen atom, or for a 5- or 6 membered         heteroaromatic ring, containing one, two or three nitrogen         atoms, or a 5 membered heteroaromatic ring, containing one         nitrogen atom and one oxygen atom or one nitrogen atom and one         sulphur atom, optionally substituted by one or more straight or         branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy         group, or halogen atom;     -   R⁴, R⁵, R⁶, and R⁷ independently mean hydrogen atom or straight         or branched C₁₋₄ alkyl group, or straight or branched C₁₋₄         alkoxy group, or hydroxy group or halogen atom, or     -   R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a         methylenedioxy group;     -   R⁸ stands for hydrogen atom or a cyano group, aminocarbonyl         group, C₁₋₄ alkoxycarbonyl group, or carboxy group;     -   R⁹ and R¹⁰ stand independently from each other for hydrogen atom         or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl         group, or a phenyl group, phenyl-(C₁₋₄)alkyl group,         thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally         substituted by a methylenedioxy group, or one or more straight         or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy         group, hydroxy group, trifluoromethyl group, cyano group or         halogen atom, or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³         group, or     -   R⁹ and R¹⁰ form together with the nitrogen atom a 3-7 membered         heterocyclic group, optionally substituted by a straight or         branched C₁₋₄ alkyl group;     -   R¹² and R¹³ stand independently from each other for hydrogen         atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆         cycloalkyl group, or a phenyl group, phenyl-(C₁₋₄)alkyl group,         thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally         substituted by a methylenedioxy group, or one or more straight         or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy         group, hydroxy group, trifluoromethyl group, cyano group or         halogen atom, or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³         group, or     -   R¹² and R¹³ form together with the nitrogen atom a 3-7 membered         heterocyclic group, optionally substituted by a straight or         branched C₁₋₄ alkyl group     -   X stands for a —CH₂— group, —NH— group, —NR¹¹— group, or a         sulphur atom or an oxygen atom or a sulpho group or a sulphoxy         group—wherein R¹¹ stands for a straight or branched C₁₋₄ alkyl         group or C₃₋₆ cycloalkyl group;     -   n stands for zero, 1 or 2     -   m stands for 1, 2, 3 or 4, and     -   o stands for zero, 1, 2, 3 or 4     -   and their salts, solvates, and optically active isomers and the         salts, solvates thereof.

A favourable group of the compounds of the general formula (IA) is formed by the compounds wherein

-   -   R¹ stands for hydrogen atom, or methyl group;     -   R² stands for hydrogen atom, or methyl group;     -   R³ stands for phenyl- or thienyl- or furyl group;     -   R⁴, R⁵, R⁶, and R⁷ mean independently hydrogen atom or straight         or branched C₁₋₄ alkyl group, or straight or branched C₁₋₄         alkoxy group, or hydroxy group or halogen atom, or     -   R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a         methylenedioxy group;     -   R⁸ stands for hydrogen atom, or cyano group;     -   R⁹ and R¹⁰ stand for methyl group; ethyl group or cyclopropyl         group or R⁹ and R¹⁰ together with the nitrogen atom form a 3-7         membered heterocyclic group, optionally substituted by a         straight or branched C₁₋₄ alkyl group,     -   X stands for —NH-group or for oxygen atom and     -   n stands for 1     -   and their salts, solvates, optically active isomers and the         salts, solvates thereof.

Especially favourable are the following compounds complying with the above criteria:

-   1-(9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)pyrrolidine; -   N,N-dimethyl-9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxamide-hemihydrate; -   N-ethyl-9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxamide-hemihydrate; -   1-(9-furfurylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine-hemihydrate; -   1-(9-thienylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine-hemihydrate;     and their salts, solvates, optically active isomers and the salts,     solvates thereof.

According to another of its aspects, the present invention also relates to pharmaceutical compositions containing as active principles the compounds of the general formula (I) or their isomers, salts and solvates, which are preferably oral compositions, but inhalable, parenteral and transdermal formulations are also subjects of the invention. The above pharmaceutical compositions may be solids or liquides, such as tablets, pellets, capsules, patches, solutions, suspensions or emulsions. The solid compositions, first of all tablets and capsules are the preferred pharmaceutical forms.

The above pharmaceutical compositions are prepared by applying usual pharmaceutical excipients and by using standard methods.

The compounds of the general formula (I) can be used in treating pathologies, in the development of which A₃ receptor plays a role.

The compounds of the present invention having selective activity on the A₃ receptor can be used in the therapeutic and/or preventive treatment of disfunctions of the heart, kidney, respiratory system, central nervous system. They inhibit the protective effect of adenosine in growing tumor cells, prevent mast cell degranulation, inhibit the cytokine production, reduce the inraocular pressure, inhibit the TNFα release, inhibit the migration of eosinophils, neutrophils and other immune cells, inhibit the bronchoconstriction and plasma extravasation.

Based on these effects, adenosine A₃ receptor antagonists of the present invention may be therapeutically useful as antiinflammatory, antiasthmatic, antiischemic, antidepressant, antiarrhytmic, renal protective, antitumor, antiparkinson and cognitive enhancing drugs. They also may be useful in the treatment or prevention of miocardial reperfusion injury, chronic obstructive pulmonary disease (COPD) and adult respiratory distress syndrome (ARDS) including chronic bronchitis, pulmonary emphysema or dyspnea, allergic reactions (e.g. rhinitis, poison ivy induced responses, urticaria, scleroderma, arthritis) other autoimmune diseases, inflammatory bowel disease, Addison's disease, Crohn's disease, psoriasis, rheumatism, hypertension, neurogical function disorders, glaucoma and diabetes (K. N. Klotz, Naunyn-Schmiedberg's Arch. Pharmacol. 362:382, 2000; P. G. Baraldi és P. A. Borea, TiPS 21:456, 2000).

The compounds of the present invention may be preferable used for the treatment of diseases such as asthma, COPD and ARDS, glaucoma, tumor, allergic and inflammatory diseases, ischemia, hypoxia, arrythmia and renal diseases.

According to another of its aspects, the present invention relates to the use of the compounds of the general formula (I) in the treatment of the above pathologies. Suggested daily dose is 0,1-1000 mg active ingredient depending on the nature and severeness of the disease and on sex, weight etc. of the patient.

Further subject of the invention is the preparation of the compounds of the general formula (I) and of the intermediates of the general formulae (II) and (III).

The intermediates of the general formulae (II) and (III) which are used in the preparation process according to the invention, are novel. Substituents of the general, formulae (II), (III), (IV) and (V) have the meanings as defined above.

In the process according to our invention a compound of the formula (VIII ) is acylated with an acid of the general Formula (II), or a reactive derivative thereof according to the acylation reactions known in the organic chemistry. As acylating agents acid halogenides or mixed anhydrides are used and the compound of the general formula (I) thus obtained is, if desired, transformed into its salts, solvates or, liberated from its salt, solvate and separated into its geometric or optical isomers.

Substituents of the compounds of the general formula (I) may be transformed into each other by known methods.

The preparation of the mixed anhydride used in the acylation reaction is carried out with pivaloyl chloride, preferable in the presence of an organic base, preferably triethylamine in chloroform, although other methods know form the organic chemistry can also be used. The acylation can be carried out within a wide temperature range, preferably between 0° C.-100° C.

The compounds of the general formula (II)—wherein the meanings of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, X and n are as defined above—can be obtained by several known methods, among them the one demonstrated in Scheme 1, by selective hydrolysis of the compounds of the formula (III), by using selective hydrolysing processes known in the organic chemistry. For hydrolysing agent preferably alkali hydroxides can be applied, but other agents helping the hydrolysis of esters can also be used.

The compounds of the general formula (II)—wherein the meanings of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, X and n are as defined above and R¹⁴ stands for Cab alkyl group—can be prepared from the compounds of the formula (IV)—by using methods known per se (I. R. Ager and R. Westwood, J. Med. Chem. 31, 1098, (1988)).

The compounds of the general formula (IV)—wherein the meanings of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸ and X and n are as defined above—can be prepared from the compounds of the formula (V), by using methods known per se (an Zhang, Bioorg. and Med. Chem. Lett., 10, 2825, (2000)).

The compounds of the general formula (V)—wherein the meanings of R⁴, R⁵, R⁶, R⁷ and R⁸ are as defined above—can be prepared from the compounds of the formula (VI), by using methods known per se (D. L. Leysen, J. Heterocyclic Chem., 24, 1611, (1987)).

The compounds of the general formula (VI)—wherein the meanings of R⁴, R⁵, R⁶, R⁷ and R⁸ are as defined above—can be prepared by using methods known per se (Pfizer (Inc) U.S. Pat. No. 4,175,193).

The compounds of the invention, of the general formulae (I), (II), (III), (IV) and (V), their preparation and biological activity are demonstrated in the following Examples, without limiting the scope of claims to the Examples.

FIG. 1 shows compounds of formula (I),

FIG. 2 shows compounds of formula (II),

FIG. 3 shows compounds of formula (III),

FIG. 4 shows compounds of formula (IV),

FIG. 5 shows compounds of formula (V),

FIG. 6 shows compounds of formula (VI),

FIG. 7 shows compounds of formula (VII),

FIG. 8 shows compounds of formula (VIII).

EXAMPLES Example 1 1-(9-Benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine

In general formula (I) R¹ and R² stand for hydrogen atoms, R³ for phenyl group, R⁴, R⁵, R⁶ and R⁷ stand for hydrogen atom, R⁹ and R¹⁰ form together a 1,3-butandiyl group, R⁸ stands for cyano group, the meaning of X is —NH group n is 1.

a.) 2-Amino-3-cyano-4-chloroquinolin

The mixture of 10 g of 2-amino-3-cyano-4-hydroxyquinolin and 15 ml of phosphoryl chloride is heated under stirring at 110° C. The reaction mixture is cooled down, poured onto 100 ml of ice-water and neutralized with 60 ml of 10% sodium hydroxide solution. The resulting yellow precipitate is filtered off, washed with 50 ml of water. After drying 7.5 g of the title compound- is obtained, mp.: 210° C.

NMR, δ_(H) (400 MHz, DMSO-d₆): 7.21 ppm, (s, 2H, NH₂), 7.35-7.40 ppm, (dd, 1H, 6-H), 7.53-7.57 ppm, (d, 1H, 5-H), 7.70-7.75 ppm, (dd, 1H, 7-H), 7.93-7.98 ppm, (d, 1H, 8-H)

b.) 2-Amino-3-cyano-4-benzylaminoquinolin

5 g of 2-amino-3-cyano-4-chloroquinolin and 11 ml of benzylamine are heated under stirring at 130° C. The reaction mixture is poured onto 50 ml of water, the resulting precipitate is filtered off, washed with 50 ml of water. The pale-yellow precipitate is recrystallized from dimethylformamide to obtain 5.2 g of the title compound. Mp.: 206° C.

NMR, δ_(H) (400 MHz, DMSO-d₆): 5.02-5.03 ppm, (d, 2H, N—CH₂), 6.22 ppm, (s, 2H, NH₂), 7.14-7.16 ppm, (dd, 1H, 6-H), 7.24-7.26 ppm,(dd,1H, 5-H), 7.30 ppm, (s, 5H, Ph), 7.50-7.52 ppm, (dd, 1H, 7-H), 8.16-8.19 ppm, (d, 1H, 8-H), 8.30-8.33 ppm, (t, 1H, NH)

Using 2-aminomethylpyridine or 3-aminomethylpyridine or 4-aminomethylpyridine instead of benzylamine, the appropriate compounds of general formula IV can be obtained.

c.) Ethyl 9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylate monohydrate

To the solution of 2.74 g of 2-amino-3-cyano-4-benzylaminoquinolin in 100 ml of abs. ethanol 2.14 ml of ethyl bromopiruvate are added, under stirring at 70° C. The reaction mixture is boiled for 2 hour, than the precipitate is filtered off. The resulting white crystalline material is recrystallized from 150 ml of acetonitrile to give 1.1 g of the title compound, mp.: 112-114° C.

NMR, δ_(H) (400 MHz, DMSO-d₆): 1.32 ppm (t, 3H, COOCH₂CH₃), 4.30 ppm (q, 2H, COOCH₂CH₃), 5.09 ppm (d, 2H, PhCH₂), 7.25-7.38 ppm (m, 5H), 7.64-7.67 ppm (m, 1H), 7.85-7.88 ppm (m, 1H), 8.43-8.53 ppm (m, 3H), 9.04 ppm (s, 1H, 3-H).

d.) 9-Benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid

The mixture of 2.71 g. ethyl 9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylate monohydrate, 42 ml ethanol and 40 ml of 10% sodium hydroxide solution is stirred for 6 hours on 25° C. To the thick suspension 100 ml water are added and the pH of the suspension is acidified to value 3 with a 96% acetic acid solution. The pale-yellow crystalline material is filtered off, washed with 3×25 ml water, and dried.Thus 2.3 g of the title compound are obtained Mp.:178-182° C.

NMR, δ_(H) (200 MHz, DMSO-d₆): 5.09 ppm (d, 2H, PhCH₂), 7.22-7.40 ppm (m, 5H), 7.59-7.67 ppm (m, 1H), 7.81-7.89 ppm (m, 1H), 8.37-8.54 ppm (m, 3H), 8.90 ppm (s, 1H, 3-H).

e. 1-(9-Benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine

To the mixture of 1.71 g. 9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid, 15 ml chloroform and 0.8 g triethylamin 0.6 g pivaloyl chloride in 10 ml chloroform are dropped, under stirring within 15 minutes at 5° C. The reaction mixture is stirred for 1 hour at 5° C., after that the mixture of 0.4 g pyrrolidine, 10 ml chloroform and 0.8 ml triethylamine is added to it. The mixture is stirred for 7 hours at 25°, diluted with 100 ml chloroform, extracted with 50 ml water, 50 ml of 5% sodium-hydrogen carbonate solution, and 50 ml water, dried on sodium-sulfate and evaporated in vacuo. The pale-yellow crystalline material is recrystallized from N,N-dimethylformamide to obtain 0.7 g of the title compound. Mp.: 206° C.

NMR, δ_(H) (400 MHz, DMSO-d₆): 1.79-1.92 ppm (m, 4H), 3.47-3.50 ppm (m, 2H), 3.95-3.98 ppm (m, 2H), 5.08 ppm (d, 2H, PhCH₂), 7.23-7.38 ppm (m, 5H), 7.62-7.65 ppm (m, 1H), 7.83-7.87 ppm (m, 1H), 8.36-8.42 ppm (m, 2H), 8.50-8.52 ppm (m, 1H), 8.80 ppm (s, 1H, 3-H).

Example 2 N,N-Dimethyl-9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxamide hemihydrate

In the general formula (I) the meaning of R¹ and R² is hydrogen atom, R³ is phenyl group, R⁴, R⁵, R⁶ and R⁷ stand for hydrogen, R⁸ means cyano group, R⁹ and R¹⁰ mean independently from each other methyl group, X means —NH-group, n is 1.

To the mixture of 1.71 g. 9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid (prepared according to example 1), 15 ml chloroform and 0.8 g triethylamin 0.6 g pivaloyl chloride in 10 ml chloroform are dropped, under stirring within 15 minutes at 5° C. The reaction mixture is stirred for 1 hour at 9° C., than the mixture of 0.45 g dimethylammonium chloride, 10 ml chloroform and 1.6 ml triethylamine is added to it. The mixture is stirred for 3 hours at 25°, than the pale-yellow crystalline material obtained according to the procedure described in example 1 is recrystallized from N,N-dimethylformamide to obtain 0.65 g of the title compound. Mp.: 262-264° C.

NMR, δ_(H) (400 MHz, DMSO-d₆): 2.98 ppm (s, 3H), 3.45 ppm (s, 3H), 5.08 ppm (d, 2H, PhCH₂), 7.23-7.38 ppm (m, 5H), 7.62-7.65 ppm (m, 1H), 7.84-7.87 ppm (m, 1H), 8.37-8.39 ppm (m, 2H), 8.50-8.53 ppm (m, 1H), 8.75 ppm (s, 1H, 3-H).

Example 3 N-Ethyl-9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxamide hemihydrate

In the general formula (I) the meaning of R¹ and R² is hydrogen atom, R³ is phenyl group, R⁴, R⁵, R⁶, and R⁷ stand for hydrogen, R⁸ means cyano group, R⁹ means hydrogen, R¹⁰ means ethyl group, X means —NH-group, n is 1.

1.71 g 9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid, prepared as described in Example 1., is transformed with 0.45 g ethylamine hydrochloride, analogously as described in previous Example ., into the title compound. After recrystallization of the pale-yellow material from 80 ml ethanol 0.62 g of the title compound, are obtained. Mp.:275-277° C.

NMR, δ_(H) (200 MHz, DMSO-d₆): 1.11 ppm (t, 3H, NHCH₂CH₃), 3.30 ppm (q, 2H, NHCH₂CH₃), 5.09 ppm (d, 2H, PhCH₂), 7.22-7.40 ppm (m, 5H), 7.60-7.67 ppm (m, 1H), 7.82-7.94 ppm (m, 2H), 8.38-8.42 ppm (m, 2H), 8.50-8.54 ppm (m, 1H), 8.82 ppm (s, 1H, 3-H).

Example 4 1-(9-Furfurylamino-10-cyano-imidazo[2-a]quinolin-2-carbonyl)-pyrrolidine hemihydrate

In the general formula (I) the meaning of R¹ and R² is hydrogen atom, R³ is 2-furyl group, R⁴, R⁵, R⁶ and R⁷ mean hydrogen, R⁹ and R¹⁰ mean together a 1,4-butandiyl group, R⁸ means cyano group, means X means —NH-group, n is 1.

a) 2-Amino-3-cyano-furfurylaminoquinolin

10 g of 2-amino-3-cyano-4-chloroquinolin and 19 ml of furfurylamine are heated under stirring at 120° C., for 3 hours. The reaction mixture is cooled to 25° C., and six times successively mixed with 50 ml of water, the resulting precipitate is filtered off and dried. The material thus obtained is recrystallized from 60 ml dimethylformamide to obtain 5.8 g of the title compound. Mp.: 206° C.

NMR, δ_(H) (200 MHz, DMSO-d₆): 4.98 ppm (d, 2H, Furil-CH₂), 6.29 ppm (s, 2H), 6.35-6.42 ppm (m, 2H), 7.10-7.18 ppm (m, 1H), 7.31-7.35 ppm (m, 1H), 7.47-7.60 ppm (m, 2H), 8.13-8.20 ppm (m, 2H).

b) Ethyl 9-furfurylamino-10-cyano-imidazo[1,2-a]quinolin-carboxylate monohydrate

To the solution of 2.64 g of 2-amino-3-cyano-4-furfurylaminoquinolin in 100 ml of abs. ethanol 2.14 ml of ethyl bromopiruvate are added, under stirring at 70° C. The reaction mixture is boiled for 2 hour, then the precipitate is filtered off. material is recrystallized 1.1 g of the title compound are obtained, mp.: 242-245° C.

NMR, δ_(H) (200 MHz, DMSO-d6): 1.33 ppm (t, 3H, COOCH₂CH₃), 4.31 ppm (q, 2H, COOCH₂CH₃), 5.05 ppm (d, 2H, Furil-CH₂), 6.40-6.43 ppm (m, 2H), 7.58-7.66 ppm (m, 2H), 7.80-7.88 ppm (m, 1H), 8.31 ppm (t, 1H), 8.41-8.45 ppm (m, 2H) 9.04 ppm (s, 1H, 3 H).

c) 9-Furfurylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid

The mixture of 2.52 g. ethyl 9-furfurylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylate monohydrate, 40 ml ethanol and 33 ml of 10% sodium hydroxide solution is stirred for 3 hours at 25° C. To the thick suspension 80 ml water are added and the pH of the suspension is acidified to value 3 with a 96% acetic acid solution. The pale-yellow crystalline material is filtered off, washed with 3×25 ml water, and dried.Thus 2.32 g of the title compound are obtained. Mp.:180-185° C., (decomposition).

NMR, δ_(H) (200 MHz, DMSO-d₆): 5.05 ppm (d, 2H, Furil-CH₂), 6.39-6.42 ppm (m, 2H), 7.56-7.64 ppm (m, 2H), 7.79-7.87 ppm (t, 1H), 8.27 ppm (t, 1H), 8.36-8.46 ppm (m, 2H), 8.93 ppm (s, 1H, 3-H).

d) 1-(9-Furfurylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine hemihydrate

To the mixture of 1.79 g. 9-furfurylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid, 15 ml chloroform and 0.8 g triethylaimin 0.6 g pivaloyl chloride in 10 ml chloroform are dropped, under stirring within 15 minutes at 5° C. The reaction mixture is stirred for 1 hour at 5° C., after that the mixture of 0.36 g pyrrolidine, 10 ml chloroform and 0.8 ml triethylamine is added to it. The mixture is stirred for 3 hours at 25°, diluted with 100 ml chloroform, extracted with 50 ml water, 50 ml of 5% sodium-hydrogen carbonate solution, and 50 ml water, dried on sodium-sulfate and evaporated in vacuo. The yellow crystalline material is recrystallized from 50 ml ethanol to obtain 0.15 g of the title compound. Mp.: 276-279° C.

NMR, δ_(H) (200 MHz, DMSO-d₆): 1.79-1.95 ppm (m, 4H), 3.47-3.54 ppm (m, 2H), 3.98-4.04 ppm (m, 2H), 5.05 ppm (d, 2H, Furil-CH₂), 6.40-6.44 ppm (m, 2H), 7.57-7.65 ppm (m, 2H), 7.80-7.88 ppm (m, 1H), 8.23 ppm (t, 1H), 8.39-8.46 ppm (m, 2H), 8.81 ppm (s, 1H, 3-F).

Example 5 1-(9-Thenylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine hemihydrate

In the general formula (I) the meaning of R¹ and R² is hydrogen atom, R³ is 2-thienyl group, R⁴, R⁵, R⁶ and R⁷ mean hydrogen, R⁹ and R¹⁰ mean together a 1,4-butandiyl group, R⁸ means cyano group, means X means —NH-group, n is 1.

a. 2-Amino-3-cyano-thenylaminoquinolin

10 g of 2-amino-3-cyano-4-chloroquinolin and 19 ml of thienylamine are heated under stirring at 115° C., for 4 hours. The reaction mixture is cooled to 25° C., and six times successively mixed with 50 ml of water, the resulting precipitate is filtered off, washed twice with 50 ml water and dried. The material thus obtained is recrystallized from 60 ml N,N-dimethylformamide to obtain 6.8 g pale-yellow title compound. Mp.: 208-209° C.

NMR, δ_(H) (200 MHz, DMSO-d₆): 5.18 ppm (d, 2H, Tienil-CH₂), 6.28 ppm (s, 2H), 6.96-7.00 ppm (m, 1H), 7.07-7.19 ppm (m, 2H), 7.31-7.42 ppm (m, 2H), 7.48-7.56 ppm (m, 1H), 8.09-8.13 ppm (m, 1H), 8.30 ppm (t, 1H).

b. Ethyl 9-thenylamino-10-cyano-imidazo[1,2-a]quinolin-carboxylate

To the solution of 5.61 g of 2-amino-3-cyano-4-thenylaminoquinolin in 200 ml of abs. ethanol 4.29 g of ethyl bromopiruvate are added, under stirring at 70° C. The reaction mixture is boiled for 2 hour, then the precipitate is filtered off. 2.54 g light beige title compound are obtained, mp.: 255-256° C.

NMR, δ_(H) (200 MHz, DMSO-d₆): 1.33 ppm (t, 3H, COOCH₂CH₃), 4.31 ppm (q, 2H, COOCH₂CH₃), 5.24 ppm (d, 2H, Tienil-CH₂), 6.96-7.00 ppm (m, 1H), 7.14 ppm (m, 1H), 7.40-7.43 ppm (m, 1H), 7.61-7.68 ppm (m, 1H), 7.82-7.90 ppm (m, 1H), 8.42-8.46 ppm (m, 3H), 9.05 ppm (s, 1H, 3-H).

c 9-Thenylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid

The mixture of 2.54 g. ethyl 9-thenylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylate, 40 ml ethanol and 33 ml of 10% sodium hydroxide solution is stirred for 6 hours at 25° C. To the thick suspension 80 ml water are added and the pH of the suspension is acidified to value 3 with a 96% acetic acid solution.

The pale-yellow crystalline material is filtered off, washed with 5×10 ml water, and dried.Thus 2.18 g of the title compound are obtained. Mp.:209-217° C. (decomposition).

NMR, δ_(H) (400 MHz, DMSO-d₆): 5.24 ppm (d, 2H, Tienil-CH₂), 8.88 ppm (s, 1H, 3-H).

d. 1-(9-Thenylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine hemihydrate

To the mixture of 1.80 g. 9-thenylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxylic acid, 10 ml chloroform and 1.1 ml triethylamin 0.87 g pivaloyl chloride in 10 ml chloroform are dropped, under stirring within 15 minutes at 5° C. The reaction mixture is stirred for 1 hour at 5° C., after that the mixture of 0.51 g pyrrolidine, 10 ml chloroform and 1.1 ml triethylamine is added to it. The mixture is stirred for 3 hours at 25°, diluted with 100 ml chloroform, extracted with 50 ml water, 50 ml of 5% sodium-hydrogen carbonate solution, and 50 ml water, dried on sodium-sulfate and evaporated in vacuo. The yellow crystalline material is recrystallized from 200 ml ethanol to obtain 0.29 g of the title compound. Mp.: 267-269° C.

NMR, δ_(H) (400 MHz, DMSO-d₆): 1.79-1.94 ppm (m, 4H), 3.48-3.51 ppm (m, 2H), 3.98-4.01 ppm (m, 2H), 5.24 ppm (d, 2H, Tienil-CH₂), 6.97-7.00 ppm (m, 1H), 7.14 ppm (m, 1H), 7.41 ppm (m, 1H), 7.61-7.65 ppm (m, 1H), 7.83-7.87 ppm (m, 1H), 8.37-8.45 ppm (m, 3H), 8.82 ppm (s, 1H, 3-H).

Structure and physical characteristics of further compounds of general formula (I) prepared by the method described in Example 1. are shown in Table I. TABLE I (I)

Mp No.: X R³ R⁹ R¹⁰ [° C.] 6. NH

H

210 7. NH

H

122 8. NH

H

104 9. NH

H

185 10. NH

H H 265 11. NH

H

269 12. NH

H

248 13. NH

H

275 14. NH

H

239 15. NH

H

149 16. NH

H

235 17. NH

H Me 280 18. NH

H

210 19. NH

H

233 20. NH

H

234 21. NH

239 22. O Me

270 23. O

233 24. S

250 25. S═O

333 26.

296

Structure and physical characteristics of the intermediates of the general formula (III) prepared by the method described in Example 1. are shown in Table (II) TABLE II III

Mp R¹ R² R³ X n [° C.] 27.

H

NH 1 146 28.

H

NH 1 145 29. H H

NH 2 34 30. H H

NH 2 32 31.

NH 0 250 32.

NH 0 128 33. H H

NH 1 45 34. H H

NH 1 54 35. H H

O 1 185 36. H H

S 1 190 37. H H

S═O 1 230 38  H H

O═S═O 1 255

Structure and physical characteristics of the intermediates of the general formula (IV) prepared by the method described in Example 1. are shown in Table (III) TABLE III (IV)

Mp No.: R¹ R² R³ R⁵ R⁶ X n [° C.] 39. H H

H H NH 1 192 40. H H

H H NH 1 202 41. H H

H H NH 1 250 42. H H

H H NH 1 167 43. H

H H NH 1 183 44. H

H H NH 1 182 45. H H

H H NH 2 172 46. H H

H H NH 2 143 47. H

H H NH 2 129 48. H

H H NH 2 136 49. H H

H H N-Me 1 212 50. H H

H H S 1 168 51. H H

H H O 1 213 52. H H

Cl H NH 1 234 53. H H

Cl H NH 1 221 54. H H

Me H NH 1 198 55. H H

MeO H NH 1 201 56. H H

H Cl NH 1 191 57. H H

OH H NH 1 246 58. H H

H H NH 1 227 59. H H

MeO H NH 1 217 60  H H

Me H NH 1 198 61. H H

Cl H NH 1 168 62.

H H NH 0 214

Structure and physical characteristics of the intermediates of the general formula (V) prepared by the method described in Example 1. are shown in Table (IV) TABLE IV

No: R⁴ R⁵ R⁶ R⁷ Mp[° C.] 63. H OH H H 360 64. H Cl H H 250 65. H H Cl H 278 66  H Me H H 283 67. H OMe H H 360 68. H H H OMe 234 69  Me H H H 246 70  H H H Me 267 71  H I H H 293

Example 72

Tablets of the following composition are made by known methods used in the pharmaceutical industry Active ingredient 25 mg Lactose 50 mg Avicel 21 mg Crospovidone  3 mg Magnesium stearate  1 mg

Biology

Methods

Human Adenosine A₃ Receptor Binding

Preparing membrane suspension: collect CHO cells expressing hA3 receptors by washing three times with ice cold PBS, centrifugate at 100×g 10 min, homogenize for 15 sec in buffer (50 mM Tris, 10 mM MgCl₂, 1 mM EDTA, pH 8.0), centrifugate at 43.000×g for 10 min (Sigma 3K30), suspense the membrane preparation in the buffer mentioned above, store the aliquots at −80 C.

Binding protocol: incubate CHO-hA₃ membrane preparation (2 μg protein content) in incubation buffer (50 mM Tris, 10 mM MgCl₂, 1 mM EDTA, 3 U/mL adenosine deaminase, pH 8.0), in the presence of 0.5 nM [¹²⁵I]AB-MECA (p-amino-benzyl-methylcarboxamido-adenosine) (100.000 cpm) and 100 μM R-PIA (N⁶-[L-2-phenylisopropyl]adenosine) to define non-specific binding or test compound in a total volume of 50 μL for 1 hr at room temperature. Filter over Whatman GF/B glass fibre filters (presoaked in 0.5% polyethylenimine for 3 hours), wash 4× with 1 mL ice-cold 50 nm Tris, 10 mM MgCl₂, 1 mM EDTA (pH 8.0) on 96-well Brandel Cell Harvester. Detection of activity: in gamma-counter (1470 Wizard, Wallac). Inhibition [%]=100-((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100

Human Adenosine A₁ Receptor Binding

Preparing membrane suspension: collect CHO cells expressing hA₁ receptors by washing three times with ice cold PBS, centrifugate at 1000×g 10 min, homogenize for 15 sec in buffer (50 mM Tris, pH 7.4), centrifugate at 43.000×g for 10 min (Sigma 3K30), suspense the membrane preparation in the buffer mentioned above, store the aliquots at −80 C.

Binding protocol: incubate CHO-hA₁ membrane preparation (50 μg protein content) in incubation buffer (50 mM Tris, 3 U/mL adenosine deaminase, pH 7.4), 10 nM [³H]CCPA (2-chloro-N⁶-cyclopenthyl-adenosine) (80.000 dpm) and 10 μM R-PIA (N⁶-[L-2-phenylisopropyl]adenosine) to define the non-specific binding or test compound in a total volume of 100 μL for 3 hr at room temperature. Filter over Whatman GF/B glass fibre filters (presoaked in 0.5% polyethylenimine for 3 hours), wash 4× with 1 mL ice-cold 50 mM Tris (pH 7.4) on 96-well Brandel Cell Harvester. Detection of activity: in 96-well plate in the presence of HiSafe-3 coctail in beta-counter (1450 Microbeta, Wallac). Inhibition [%]=100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100

Human Adenosine A_(2a) Receptor Binding

Binding protocol: incubate 7 μg of membranes (human A_(2a) adenosine receptors transfected into HEK-293 cells, source: Receptor Biology, Inc.), buffer (50 mM Tris-HCl, 10 mM MgCl₂, 1 mM EDTA, 2 U/mL adenosine deaminase, pH 7.4), 20 nM [³H]CGS-21680 (2-[p-(2-carbonylethyl)phenylethylamino]-5′-N-ethylcarboxamido-adenosine) (200.000 dpm) and 50 μM NECA (5′-N-ethylcarboxamido-adenosine) to define the non-specific binding or test compound in a total volume of 100 μl for 90 min at room temperature. Filter over Whatman GF/B glass fibre filters (presoaked in 0.5% polyethylenimine), wash 4× with 1 mL ice-cold 50 mM Tris, 10 mM MgCl₂, 1 mM EDTA, 0.9 % NaCl, pH 7.4) on 96-well Brandel Cell Harvester. Detection of activity: in 96-well plate in the presence of HiSafe-3 coctail in beta-counter (1450 Microbeta, Wallac). Inhibition [%]100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100

Human Adenosine A_(2b) Receptor Binding

Binding protocol: incubate 20.8 μg of membranes (human A_(2b) adenosine receptors transfected into HEK-293 cells, source: Receptor Biology, Inc.), buffer (50 mM Tris-HCl, 10 mM MgCl₂, 1 mM EDTA, 0.1 mM benzamidine, 2 U/mL adenosine deaminase, pH 6.5), 32.4 nM [³H]DPCPX (8-cyclopenthyl-1,3-dipropylxanthine) (800.000 dpm) and 100 μM NECA (5′-N-ethylcarboxamido-adenosine) to define non-specific binding or test compound in a total volume of 100 μL for 30 min at room temperature. Filter over Whatman GF/C glass fibre filters (presoaked in 0.5% polyethylenimine), wash 4× with 1 mL ice-50 mM Tris-HCl (pH 6.5) on 96-well Brandel Cell Harvester. Detection of activity: in 96-well plate in the presence of HiSafe-3 coctail in beta-counter (1450 Microbeta, Wallac). Inhibition [%]100−((activity in the presence of test compound−non-specific activity)/(total activity−non-specific activity))*100

Results

We consider the compounds as biologically active ones if they inhibit the binding of the radioligand on human adenosine A₃ receptors with an activity above 80% at 1 μM in our experimental conditions.

The dissociation constant (K_(d)) of [¹²⁵I]-MECA on CHO-hA₃ membrane perparation is determined by isotope saturation studies with the help of Seatchard analysis (G. Scatchard, Ann. N. Y. Acad. Sci. 51:660, 1949). The IC₅₀ is converted to an affinity constant (K_(i)) by application of the Cheng-Prusoff equation (Y. J. Cheng and W. H. Prusoff, Biochem. Pharmacol. 22:3099, 1973).

Several compounds of the general formula (I), (II), (III) and (IV) display remarkable biological effects. The compounds of the general formula (IA), defined in claim 2, as a subgroup of the general formula (I), defined in claim 1, exert the most important activities. Except of 9 compounds, their K_(i) values are not higher than 150 nM. The compounds given as examples are especially advantageous. Their K_(i) values in human adenosine A₃ receptor binding studies are between 1.6 and 0.38 nM. The K_(i) values of the most advantageous compounds are 0.52 and 0.38 nM.

The compounds possess proper bioviabilities and exert at least 1,000-fold selectivity in respect of human adenosine A₁, A₂, and A_(2b) receptor subtypes.

Further, the duration of their action at intravenous and oral administration is long enough, their ED₅₀ values are low, their toxicological and side-effect profiles are advantageous.

Data above make the compounds of the general formula (I) probable for therapeutic applications. 

1. Compounds of the general formula (I)

wherein R¹ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl group; R² stands for hydrogen atom or a straight or branched C₁₋₄ alkyl group; R³ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl group, or C₃₋₆ cycloalkyl group, or a phenyl group, thienyl group, or furyl group, optionally substituted by one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen atom, or for a 5- or 6 membered heteroaromatic ring, containing one, two or three nitrogen atoms, or a 5 membered heteroaromatic ring, containing one nitrogen atom and one oxygen atom or one nitrogen atom and one sulphur atom-, optionally substituted by one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen atom; R⁴, R⁵, R⁶ and R⁷ stand independently from each other for hydrogen atom, a straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, hydroxy group or halogen atom; or R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a methylenedioxy group; R⁸ stands for hydrogen atom or a cyano group, aminocarbonyl group, C₁₋₄ alkoxycarbonyl group, or carboxy group; R⁹ and R¹⁰ stand independently from each other for hydrogen atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl group, or a phenyl group, phenyl-(C₁₋₄)alkyl group, thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally substituted by a methylenedioxy group, or one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, hydroxy group, trifluoromethyl group, cyano group or halogen atom, or for a 5 or 6 membered heteroaromatic ring, containing one, two or three nitrogen atoms, or a 5 membered heteroaromatic ring, containing one nitrogen atom and one oxygen atom or one nitrogen atom and one sulphur atom, optionally substituted by one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen atom; or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³ group, or R⁹ and R¹⁰ form together with the nitrogen atom a 3-7 membered heterocyclic group, optionally substituted by a straight or branched C₁₋₄ alkyl group; R¹² and R¹³ stand independently from each other for hydrogen atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl group, or a phenyl group, phenyl-(C₁₋₄ )alkyl group, thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally substituted by a methylenedioxy group, or one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, hydroxy group, trifluoromethyl group, cyano group or halogen atom, or for a 5 or 6 membered heteroaromatic ring, containing one, two or three nitrogen atoms, or a 5 membered heteroaromatic ring, containing one nitrogen atom and one oxygen atom or one nitrogen atom and one sulphur atom, optionally substituted by one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen atom, or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³ group, or R¹² and R¹³ form together with the nitrogen atom a 3-7 membered heterocyclic group, optionally substituted by a straight or branched C₁₋₄ alkyl group X stands for a —CH₂— group, —NH— group, —NR¹¹— group, or a sulphur atom or an oxygen atom or a sulpho group or a sulphoxy group—wherein R¹¹ stands for a straight or branched C₁₋₄ alkyl group or C₃₋₆ cycloalkyl group; n stands for zero, 1 or 2; m stands for 1, 2, 3 or 4, and o stands for zero, 1, 2, 3 or 4 and their salts, solvates, and optically active isomers and the salts, solvates thereof.
 2. Compounds of the general formula (I) according to claim 1, wherein R¹ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl group; R² stands for hydrogen atom or a straight or branched C₁₋₄ alkyl group; R³ stands for hydrogen atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl group, or a phenyl group, thienyl group, or furyl group, optionally substituted by one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen atom, or for a 5- or 6 membered heteroaromatic ring, containing one, two or three nitrogen atoms, or a 5 membered heteroaromatic ring, containing one nitrogen atom and one oxygen atom or one nitrogen atom and one sulphur atom, optionally substituted by one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, or halogen atom; R⁴, R⁵, R⁶, and R⁷ independently mean hydrogen atom or straight or branched C₁₋₄ alkyl group, or straight or branched C₁₋₄ alkoxy group, or hydroxy group or halogen atom, or R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a methylenedioxy group; R⁸ stands for hydrogen atom or a cyano group, aminocarbonyl group, C₁₋₄ alkoxycarbonyl group, or carboxy group; R⁹ and R¹⁰ stand independently from each other for hydrogen atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl group, or a phenyl group, phenyl-(C₁₋₄)alkyl group, thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally substituted by a methylenedioxy group, or one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, hydroxy group, trifluoromethyl group, cyano group or halogen atom, or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³ group, or R⁹ and R¹⁰ form together with the nitrogen atom a 3-7 membered heterocyclic group, optionally substituted by a straight or branched C₁₋₄ alkyl group; R¹² and R¹³ stand independently from each other for hydrogen atom or a straight or branched C₁₋₄ alkyl group, or a C₃₋₆ cycloalkyl group, or a phenyl group, phenyl-(C₁₋₄)alkyl group, thienyl-(C₁₋₄)alkyl group or furyl-(C₁₋₄)alkyl group, optionally substituted by a methylenedioxy group, or one or more straight or branched C₁₋₄ alkyl group, straight or branched C₁₋₄ alkoxy group, hydroxy group, trifluoromethyl group, cyano group or halogen atom, or for a —(CH₂)_(m)—OH or —(CH₂)_(o)—NR¹²R¹³ group, or R¹² and R¹³ form together with the nitrogen atom a 3-7 membered heterocyclic group, optionally substituted by a straight or branched C₁₋₄ alkyl group X stands for a —CH₂— group, —NH— group, —NR¹¹— group, or a sulphur atom or an oxygen atom or a sulpho group or a sulphoxy group—wherein R¹¹ stands for a straight or branched C₁₋₄ alkyl group or C₃₋₆ cycloalkyl group; n stands for zero, 1 or 2; m stands for 1, 2, 3 or 4, and o stands for zero, 1, 2, 3 or 4 and their salts, solvates, and optically active isomers and the salts, solvates thereof.
 3. Compounds of the general formula (I) according to claim 1 wherein R¹ stands for hydrogen atom, or methyl group; R² stands for hydrogen atom, or methyl group; R³ stands for phenyl- or thienyl- or furyl group; R⁴, R⁵, R⁶, and R⁷ mean independently hydrogen atom or straight or branched C₁₋₄ alkyl group, or straight or branched C₁₋₄ alkoxy group, or hydroxy group or halogen atom, or R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a methylenedioxy group; R⁸ stands for hydrogen atom, or cyano group; R⁹ and R¹⁰ stand for methyl group, ethyl group or cyclopropyl group or R⁹ and R¹⁰ together with the nitrogen atom form a 3-7 membered heterocyclic group, optionally substituted by a straight or branched C₁₋₄ alkyl group, X stands for —NH-group or for oxygen atom and n stands for 1 and their salts and solvates, optically active isomers and their salts and solvates.
 4. Compounds according to claim 1 as follows: 1-(9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)pyrrolidine; N,N-dimethyl-9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxamide-hemihydrate; N-ethyl-9-benzylamino-10-cyano-imidazo[1,2-a]quinolin-2-carboxamide-hemihydrate; 1-(9-furfurylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine-hemihydrate; 1-(9-thienylamino-10-cyano-imidazo[1,2-a]quinolin-2-carbonyl)-pyrrolidine-hemihydrate; and their salts, solvates, optically active isomers and the salts, solvates thereof.
 5. Process for the preparation of a compound of the general formula (I),

its salts, solvates, optically active isomers and their salts and solvates-wherein in the formula R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, X, n, m and o have the same meaning as defined in claim 1, which comprises acylating a compound of the general formula (VIII),

wherein R⁹ and R¹⁰ have the same meaning as defined in claim 1, with an acid of the general formula (II),

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, X and n have the same meaning as defined in claim 1, or a reactive derivative thereof and if desired transforming the substituents of the compound of the general formula (I) thus obtained in each other by methods known per se and/or transforming the compound of the general formula (I) thus obtained into its salts, or solvates, or liberating it from its salts or solvates and/or separating it into its optically active isomeric forms or transforming the optically active forms into the racemic form.
 6. Process according to claim 5 which comprises carrying out the acylation in an organic solvent, in the presence of a base.
 7. Process according to claim 5 which comprises using an acid halide or anhydride as the reactive derivative of the acid.
 8. Process according to claim 5 which comprises using as organic solvent halogenated hydrocarbons.
 9. Process according to claim 5 which comprises using as base an organic base.
 10. Pharmaceutical compositions containing as active ingredient one or more compounds of the general formula (I)—wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, X and n have the same meaning as defined in claim 1—or their salts, solvates, or optically active isomers and the salts, solvates thereof, in admixture with one or more excipients used in the pharmaceutical industry.
 11. Pharmaceutical compositions containing as active ingredient one or more compounds of claim 3 in admixture with one or more excipients.
 12. Pharmaceutical composition containing as active ingredient one or more compound of claim 4 in admixture with one or more excipients.
 13. A method for the treatment of diseases in development of which the receptor A₃ plays a role which comprises administering to a patient in need of such treatment an effective amount of a compound according to claim
 1. 14. A method according to claim 13 for the treatment of diseases of the heart, kidney, respiratory organs and central nervous system, for the inhibition of the protection of adenosine in growing tumor cells, prevention of mast cell degranulation, inhibition of the cytokine production, reduction of intraocular pressure, inhibition of the TNFα release, inhibition of eosinophil, neutrophil and other immune cell migration, inhibition of bronchoconstriction and plasma extravasation.
 15. A method according to claim 14 for the treatment of inflammatory diseases, asthma, ischemia, depression, arrhythmia, renal diseases, tumors, Parksinsons disease, and for cognitive enhancement, and for the treatment or prevention of miocardial referfusion injury, chronic obstructive pulmonary disease (COPD), adult respiratory distress syndrome (ARDS), chronic bronchitis, pulmonary emphysema or dyspnea, allergic reactions, other autoimmune diseases, inflammatory bowel disease, Addison's disease, Crohn's disease, psoriasis, rheumatism, hypertension, neurogical functions disorders, glaucoma and diabetes.
 16. A method according to claim 15 for the treatment of asthma, COPD and ARDS, glaucoma, tumor, allergic and inflammatory diseases, ischemia, hypoxia, arrhythmia and renal diseases.
 17. Compounds of the general formula (II)

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, X and n have the same meaning as defined in claim
 1. 18. Compounds of the general formula (III)

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, X and n have the same meaning as defined in claim 1, and R¹⁴ stands for C₁₋₄ alkyl group.
 19. Compounds of the general formula (I) according to claim 2 wherein R¹ stands for hydrogen atom, or methyl group; R² stands for hydrogen atom, or methyl group; R³ stands for phenyl- or thienyl- or furyl group; R⁴, R⁵, R⁶, and R⁷ mean independently hydrogen atom or straight or branched C₁₋₄ alkyl group, or straight or branched C₁₋₄ alkoxy group, or hydroxy group or halogen atom, or R⁴ and R⁷ stand for hydrogen atom and R⁵ and R⁶ form together a methylenedioxy group; R⁸ stands for hydrogen atom, or cyano group; R⁹ and R¹⁰ stand for methyl group, ethyl group or cyclopropyl group or R⁹ and R¹⁰ together with the nitrogen atom form a 3-7 membered heterocyclic group, optionally substituted by a straight or branched C₁₋₄ alkyl group, X stands for —NH-group or for oxygen atom and n stands for 1 and their salts and solvates, optically active isomers and their salts and solvates.
 20. Process according to claim 6 which comprises using an acid halide or anhydride as the reactive derivative of the acid.
 21. Process according to claim 6 which comprises using as organic solvent halogenated hydrocarbons.
 22. Process according to claim 8 which comprises using chloroform.
 23. Process according to claim 21 which comprises using chloroform.
 24. Process according to claim 6 which comprises using as base an organic base.
 25. Process according to claim 7 which comprises using as base an organic base.
 26. Process according to claim 8 which comprises using as base an organic base.
 27. Process according to claim 9 which comprises using triethylanine.
 28. Process according to claim 24 which comprises using triethylanine.
 29. Process according to claim 25 which comprises using triethylanine.
 30. Process according to claim 26 which comprises using triethylanine.
 31. Pharmaceutical composition containing as active ingredient one or more compound of claim 2 in admixture with one or more excipients.
 32. Pharmaceutical composition containing as active ingredient one or more compound of claim 19 in admixture with one or more excipients.
 33. A method for the treatment of diseases in development of which the receptor A₃ plays a role which comprises administering to a patient in need of such treatment an effective amount of a compound according to claim
 2. 34. A method for the treatment of diseases in development of which the receptor A₃ plays a role which comprises administering to a patient in need of such treatment an effective amount of a compound according to claim
 3. 35. A method for the treatment of diseases in development of which the receptor A₃ plays a role which comprises administering to a patient in need of such treatment an effective amount of a compound according to claim
 4. 36. A method for the treatment of diseases in development of which the receptor A₃ plays a role which comprises administering to a patient in need of such treatment an effective amount of a compound according to claim
 19. 